The Ballard Maturational Assessment, Ballard Score, or Ballard Scale is a commonly used technique of gestational age assessment. It assigns a score to various criteria, the sum of all of which is then extrapolated to the gestational age of the baby. These criteria are divided into Physical and Neurological criteria. This scoring allows for the estimation of age in the range of 26 weeks-44 weeks. The New Ballard Score is an extension of the above to include extremely pre-term babies i.e. up to 20 weeks.

The scoring relies on the intra-uterine changes that the fetus

Fetus

A fetus is a developing mammal or other viviparous vertebrate after the embryonic stage and before birth.In humans, the fetal stage of prenatal development starts at the beginning of the 11th week in gestational age, which is the 9th week after fertilization.-Etymology and spelling variations:The...

 undergoes during its maturation. Whereas the neurological criteria depend mainly upon muscle tone, the physical ones rely on anatomical changes. The neonate (less than 28 days of age) is in a state of physiological hypertonia

Hypertonia

Hypertonia a condition marked by an abnormal increase in muscle tension and a reduced ability of a muscle to stretch. It is caused by lesions to upper motor neurons in the central nervous system, which carry information from the central nervous system to the muscles and control posture, muscle...

. This tone increases throughout the fetal growth period, meaning a more premature

Premature

Premature can refer to:*Premature aging: see Senescence*Premature birth or prematurity: see Preterm birth*Premature ejaculation*Premature menopause*Premature stop codon: see Nonsense mutation*Premature ventricular contraction...

 baby would have lesser muscle tone.

It was developed in 1979.

The Physical criteria

These are:

1. Skin
   Skin
   -Dermis:The dermis is the layer of skin beneath the epidermis that consists of connective tissue and cushions the body from stress and strain. The dermis is tightly connected to the epidermis by a basement membrane. It also harbors many Mechanoreceptors that provide the sense of touch and heat...
   
   
2. Ear/Eye
3. Lanugo Hair
   Lanugo
   Lanugo is fine, downy hair as a type of fur. It is often found in teratomas .-Fetal development:Lanugo grows on fetuses as a normal part of gestation, but is usually shed and replaced by vellus hair at about 33 to 36 weeks of gestational age...
   
   
4. Plantar Surface
5. Breast bud
6. Genitals

Scoring

Each of the above criteria are scored from 0 through 5, in the original Ballard Score. The scores were then ranged from 5 to 50, with the corresponding gestational ages being 26 weeks and 44 weeks. An increase in the score by 5, increases the age by 2 weeks. The New Ballard Score allows scores of -1 for the criteria, hence making negative scores possible. The possible scores then range from -10 to 50, the gestational range extending up to 20 weeks.
(A simple formula to come directly to the age from the Ballard Score is
Age=(2*score+120) /5)